This may not be true, but it may also be caused by overdue repayment. If the overdue repayment is frozen, it needs to be repaid in time after freezing, and you need to contact the bank to help unfreeze it. If the bank unfreezes the credit card, it can be used normally, so it is not a black account. However, if the bank does not let the cardholder continue to use this card, the user is likely to be considered as a black account by the bank.
However, if the bank determines that the user has a serious current behavior, it will immediately freeze the credit card, and at the same time, it will require the user to repay in full. After repayment, the user is still not allowed to use the credit card, so the bank will identify the cardholder as a black account.